1. Field of the Invention
The present invention relates to a battery system for controlling a plurality of battery packs. The present invention also relates to a battery pack used in such a battery system.
2. Description of Related Art
A conventional battery system is disclosed for example in Japanese patent Laid-Open No. 2003-209932 (pages 4-6 and FIG. 1). This battery system is mounted for example in a vehicle and has a plurality of battery packs. An operation state of each battery pack is controlled at a battery ECU (Engine Control Unit) provided at each battery pack, and any abnormal state is detected. At each battery pack ECU, address setting terminals are provided having the same number of address bits as the number of battery packs that are provided. In addition, address lines are provided having the same number as the bits and the address setting terminals.
Each address line is connected in different combinations to the address setting terminals of each battery ECU respectively. As such, ID numbers corresponding to connecting locations of the battery packs are detected through the address lines from the vehicle side. Thus, it is possible to identify a battery pack in an abnormal state and to perform a control from the vehicle side such as to disconnect or disable the abnormal battery pack. In addition, by connecting the predetermined combination of the address lines to a terminal block to which a battery pack is connected, the ID number of the connecting location can be made constant even if the battery pack is replaced.
However, according to the above-described conventional battery system, it is necessary to provide the same number of address setting terminals and address lines as the number of bits corresponding to the number of battery packs in order to detect the connecting locations of the battery packs. Thus, the electronic circuit of such conventional system is complex and costly.
Therefore, an object of the invention is to provide a battery system that can reduce cost by detecting connecting locations of the battery packs with a simple structure, and also to provide a battery pack used in such a battery system.